Intrinsically Porous Polymers for Gas Separations

s by speakers Day 1: 19/01/2022 Theme: Gas Separation 1. Chemistry and engineering of graphene at Å scale for energy-efficient gas separation Kumar Varoon Agrawal, GAZNAT Chair of Advanced Separations, EPFL, Switzerland. High-performance molecular-sieving membranes are expected to play a crucial role in improving the energy efficiency of the gas separation processes reducing the related carbon emission. Toward this goal, our laboratory at EPFL (http://las.epfl.ch) is engaged in chemistry and engineering of two-dimensional materials at the angstrom length scale to address the challenges in the scalable synthesis of membranes hosting atom-thick selective layer separating molecules based on their relative diffusivities through the custom-designed nanopores. In this seminar, I will present the work on the synthesis of nanoporous graphene membranes by the top-down and the bottom-up synthetic strategies. I will discuss key challenges in the design of such membranes followed by strategies that permit the incorporation of vacancy defects (nanopores) at a high density but also with a narrow pore-size-distribution with a molecular differentiation resolution below 0.3 Å, leading to the realization of record-high performance in post-combustion carbon capture [1-6]. I will discuss the fabrication of graphene membranes based mechanical reinforcement strategy that allows one to scale-up membranes for gas separation [4, 7]. Finally, I will describe the ongoing pilot plant demonstrator project for the postcombustion capture. References 1. Science Advances 2019, 5, eaav1851. 2. Energy & Environmental Sciences 2019, 12, 3305–3312. 3. Science Advances 2021, 7 (9), eabf0116. 4. Nature Communications 2018, 9, 2632. 5. ACS Nano 2021, 15 (8), 13230–13239. 6. Proc. Natl. Acad. Sci. 2021, 118 (37), e2022201118. 7. Journal of Membrane Science 2021, 618, 118745. 2. Intrinsically Porous Polymers for Gas Separations Zachery P. Smith, Professor of Chemical Engineering, MIT, USA. Gas separation membranes present an opportunity to replace centuries-old separation technologies and to help achieve a low-carbon future. However, there are various challenges in designing materials with high flux, high selectivity, and stability to relevant process conditions. In this presentation, two opportunities will be discussed for designing the next generation of gas separation membranes. First, the use of sorption-selective functional groups and the concept of free volume manipulation will be presented to demonstrate a method to control chemistry and microstructure at a sub-nanometer length scale. Second, an approach of using bottlebrush polymers with pre-designed side chains will be presented to demonstrate the role of side-chain structure for targeted separation applications. In addition to these studies, a short introduction to theory and applications of gas separation membranes will be discussed to highlight the exciting and interdisciplinary opportunities to leverage chemistry, chemical engineering, and materials science to address important societal and technological challenges needed for a clean-energy and low-carbon future. 3. Novel Mixed Matrix Polymer Membranes for Critical Gas Separations Sanat K Kumar Department of Chemical Engineering Columbia University New York, NY Polymeric membranes, which present an efficient solution for emergent technologies, such as CO2 capture and natural gas purification, are effective at the selective and efficient transport of gases. The field of polymer membrane design is primarily based on empirical observation, which limits the discovery of new, advanced materials most appropriate for separating a given gas pair. Instead of relying on exhaustive experimental investigations, we apply machine learning on a limited set of experimental gas permeability data for six different gases in ~700 polymeric constructs that have been measured to date to predict the behavior of over 10,000 homopolymer architectures that are currently known. This machine learning technique, which only uses a small body of experimental data (and no simulation data) to accurately predict the behavior of large classes of polymers, evidently represents a novel means of exploring the vast phase space available for polymer membrane design in a manner that is orders of magnitude more efficient than typical empirical observations. However this approach suggests that the current polymers used in membrane applications represent the best that this template can provide – thus new platforms are required to improve performance. We thus propose novel membranes based on polymers mixed with nanoparticles (GNPs). The issues raised by these methods and ways to use and leverage them to systematically improve performance is the second major focus of my tutorial. Day 2: 20/01/2022 Theme: Water Purification 4. Affordable clean water using advanced materials